Prepare for Pytest v8

The behavior of pytest.warns has changed, particularly with regards to handling of additional warnings

Author: ksunden

lib/matplotlib/tests/test_backend_pdf.py

@@ -3,6 +3,7 @@
 import io
 import os
 from pathlib import Path
+import warnings
 
 import numpy as np
 import pytest
@@ -84,6 +85,9 @@ def test_multipage_keep_empty(tmp_path):
     os.chdir(tmp_path)
 
     # test empty pdf files
+    # Due to order of `with` block execution, a warning for unclosed file is raised
+    # but the pytest.warns must happen before the PdfPages is created
+    warnings.filterwarnings("ignore", category=ResourceWarning)
 
     # an empty pdf is left behind with keep_empty unset
     with pytest.warns(mpl.MatplotlibDeprecationWarning), PdfPages("a.pdf") as pdf:

lib/matplotlib/tests/test_colors.py

@@ -147,8 +147,7 @@ def test_double_register_builtin_cmap():
     with pytest.raises(ValueError, match='A colormap named "viridis"'):
         with pytest.warns(mpl.MatplotlibDeprecationWarning):
             cm.register_cmap(name, mpl.colormaps[name])
-    with pytest.warns(UserWarning):
-        # TODO is warning more than once!
+    with pytest.warns(UserWarning), pytest.warns(mpl.MatplotlibDeprecationWarning):
         cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
 
 

lib/matplotlib/tests/test_rcparams.py

@@ -106,14 +106,12 @@ def test_rcparams_update():
     rc = mpl.RcParams({'figure.figsize': (3.5, 42)})
     bad_dict = {'figure.figsize': (3.5, 42, 1)}
     # make sure validation happens on input
-    with pytest.raises(ValueError), \
-         pytest.warns(UserWarning, match="validate"):
+    with pytest.raises(ValueError):
         rc.update(bad_dict)
 
 
 def test_rcparams_init():
-    with pytest.raises(ValueError), \
-         pytest.warns(UserWarning, match="validate"):
+    with pytest.raises(ValueError):
         mpl.RcParams({'figure.figsize': (3.5, 42, 1)})
 
 

lib/matplotlib/tests/test_ticker.py

@@ -3,6 +3,7 @@
 import locale
 import logging
 import re
+import warnings
 
 import numpy as np
 from numpy.testing import assert_almost_equal, assert_array_equal
@@ -914,6 +915,9 @@ def test_mathtext_ticks(self):
             'axes.formatter.use_mathtext': False
         })
 
+        # Glyph warning unrelated
+        warnings.filterwarnings("ignore", category=UserWarning, message="Glyph 8722")
+
         with pytest.warns(UserWarning, match='cmr10 font should ideally'):
             fig, ax = plt.subplots()
             ax.set_xticks([-1, 0, 1])